A lot of GT's won't have a hump. Only some males get them, and out of those a very select few will have a large hump. If the GT is a nice fish, $30 is fare. GT's come in all different genetic quality. For instance... Wild caught specimen generally look the best when they grow up. Most will remain vibrant. Petsmart GT's start to break down physically after a few months. Far east imports are usually hormone induced. Typically they are blue with a red tail, but they will lose their colors and won't be as vibrant. when larger